Selective catalytic reduction technology has been used in conjunction with reducing nitrogen oxides present in the exhaust of internal combustion engines. Many vehicles utilizing internal combustion engines as a prime mover are also equipped with exhaust after-treatment devices for reducing nitrogen oxide emissions. Some of these systems are constructed using a separate container mounted to the vehicle for storing the reductant, a reductant injector and a selective catalytic reduction catalyst. Those systems typically incorporate a reductant pump that delivers the reductant from the container to the injector. While these systems may have performed well in the past, it may be desirable to provide a selective catalytic reduction system that more effectively controls the reductant pump to minimize pump noise and manage actuator cool down relative to exhaust gas temperature.